Yes, they're not exposed graphite piles.
Yes, the steel pressure vessel is probably going to hold. At least, mostly.
But they guys in Tokyo who are in "full-scale panic" are probably in a better position to know what's going on and how bad things are than a writer for TheReg in the UK.
The plant is 40 years old. It doesn't have the latest safety measures that many later plants have. At least one reactor was scheduled to be shut down this month. Who knows whether some important maintenance was put off as being unnecessary or not cost-effective.
http://en.wikipedia...._nuclear_accident
Even anal-retentive engineers and maintenance technicians make mistakes. These TEPCO plants have had some issues in the past - http://www2.jnes.go...._power_index.html and http://www2.jnes.go...._power_index.html
All commercial nuclear plants that have suffered major accidents have experienced things that the designers didn't intend or didn't consider. That's the nature of complex engineering projects. Perhaps the steel containment vessel will perform admirably for all of these at-risk reactors. I suspect and hope that they will. But I'm not at all pleased by all of the "everything's fine, it's working as designed, it's no big deal, what's everyone upset about" attitude in much of the reporting on this. This is a big deal and wasn't supposed to happen. The safety measures were supposed to ensure that the fuel rods didn't suffer from lack of coolant even in severe circumstances.
The world needs to get off of burning stuff for power and transportation. Nuclear should probably have a larger role, but it's not at all clear to me that large-scale power reactors are the way to go. There comes a point where there are too many conceivable failure mechanisms that could result in large enough probability of vast contamination of the environment for the technology to be economically viable.
The Shuttle solid-rocket booster O-rings had a 100% "safety margin" when they were half burned through, too... We know how that turned out. :-(
The nuclear advocates out there in the press need to take what's happening to TEPCO's plants seriously. They shouldn't take the concerns as being fears of Luddites who don't know any better. If this disaster gets even a little bit worse, it may spell the end of commercial nuclear power plants in the democratic world. A substantial fraction of the population (and maybe a majority) has to support it for it to go forward, and they won't if there are continued explosions and stories in the press that the operators can't do what they say they need to do - no matter what people who "know better" say.
"Who you gonna believe? Me, or your own lying eyes?"
My $0.02.
Cheers,
Scott.
